One of the most advanced technologies in the field of water treatment in the world in recent decades is water filtration technology based on the principle of reverse osmosis (Reverse Osmosis, RO) with filter pores of 0.1 Nanometer size. , similar to the mechanism of human kidneys, can filter all bacteria as well as impurities in water (RO membrane is also known as artificial kidney). This technology was invented by American scientist ORIRAJIN in 1950. Initially, this technology was mainly used for water filtration purposes to serve human space travel. NASA used RO technology to recover and clean the urine and wastewater of astronauts on the space shuttle, recirculating all of this water for drinking.
Later it was applied in many other fields, such as in healthcare for hemodialysis, pure water filtration for laboratories, and for the electronic circuit production industry (ultra-pure water). Especially in saline areas or without fresh water, long-term seagoing ships cannot lack water purifiers with reverse osmosis technology to filter salt water into fresh water and are now serving daily drinking water such as water. familiar bottled purified water products. RO water filtration technology has become popular in many parts of the world and is filtering any water source anywhere into pure water, helping to prevent disease and poisoning for hundreds of millions of people around the world.
Recently, scientists are developing nanofiltration membranes, with a pore size of about 0.01 micrometers. This product is considered to also have the ability to filter water for drinking. However, according to many studies, a filter pore size of 0.01 micrometer still cannot completely remove minerals, including heavy metals and toxic organic substances in water. . Therefore, many people still doubt the ability to ensure the safety of water filtered with nanotechnology, especially for input water sources containing many toxic heavy metals.
Filtration is the process of separating solids (suspended residue) from water. When water mixed with suspended impurities passes through the filter material, the residue can be retained for the water to pass through, resulting in clear water containing no or very little suspended sediment. In the water treatment chain for drinking, drinking, and domestic use, filtering is usually the final stage to thoroughly clarify the water.